(CAD model of the blocking cam of the Barrier Model)

The pin inserted into the case is initially in contact with the rear arm of the cam (the one on which the spring is fixed) and makes the cam rotate around its own hinge.

 

For a fixed value of the pin motion the front arm of the cam slips into the cavity of the pin and, at the same time the contact between the pin and the rear arm of the cam ceases, allowing the mechanism to continue in its motion.

 

It is not possible to trigger the mechanism by inserting an object that is different from the pin because the spring flap occurs after the contact between the front arm and cam has happened.

 

In this case, with the entrance of an external object, the front arm will push down it, not allowing the contact between it and the cam itself.

 

Here it is shown the video of the working principle:

(CAD assembly of the Barrier Model)

 

(Principles of working of the secondary model, the Barrier)

 

Laboratorio Progettuale CAD - Academic year 2015-2016